The doors to CERN, the particle physics lab near Geneva where the Higgs boson was discovered last year, are closed to most folks. But the researchers there let in a team from Google Maps Street View, and now anyone can tour the Large Hadron Collider and other CERN experiments in 360-degree photo panoramas online.

Virtual visitors can “walk” through a tunnel housing part of the collider’s 27-kilometer-long particle accelerator. Or you can explore brightly painted particle detectors such as the ...